struvite and calcium-magnesium-phosphate

Regenerative bone implants should be completely replaced by new bone within a period of time corresponding to the growth rate of native bone. To meet this requirement, suitable biomaterials must be biodegradable and promote osteogenesis. The combination of slowly degrading but osteoconductive calcium phosphates (CPs) with rapidly degrading and mechanically more resilient magnesium phosphates represents a promising material class for this purpose. In order to create the best possible conditions for optimal implant integration, microporous calcium magnesium phosphate (CMP) cements were processed using 3D powder printing. This technique enables the production of a defect-adapted implant with an optimal fit and a high degree of open porosity to promote bone ingrowth. Four different compositions of 3D printed CMP ceramics were investigated with regard to essential properties of bone implants, including chemical composition, porosity, microstructure, mechanical strength, and cytocompatibility. The ceramics consisted of farringtonite (Mg

Topics: Bone Cements; Bone Substitutes; Calcium Phosphates; Humans; Magnesium; Materials Testing; Phosphates; Struvite

The present study aimed to investigate the chemical composition of urinary calculi in people living in the northern border area of Saudi Arabia and to formulate suggestions for prevention of renal stones. Urinary stones were obtained from patients attending the Urology Departments of Prince Abdul Aziz Bin Musaad Hospital and Central Hospital, Arar, Saudi Arabia. Stones were analyzed using kit for semi-quantitative colorimetric determination of carbonate, calcium, magnesium, ammonium, oxalate, phosphate, uric acid and cysteine; manufactured by LTA s.r.l. Milano 15/F, 20060 Bussero (Milano), Italy. From a total of 55 urinary stones, 49 (89%) were retrieved from males, while 6 (11%) from females. Ages of patients ranged from 15 to 75 years with the mean of 50.22}14.46 and majority of patients were between 31-50 years (69.08%). Most of the patients were overweight (70.91 %) in both the genders. Calcium oxalate stones were 60%, uric acid 18.18% and calcium phosphate 10.90%, while other forms of stones were scarce. It is concluded that upper urinary tract stones were predominant, comprising mostly of calcium oxalate and urate, which could be prevented by control of obesity; moderate intake of meat, dairy products, fruit vegetables (with minimal oxalates); and plenty of fluids.

Topics: Adolescent; Adult; Aged; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Female; Humans; Male; Middle Aged; Phosphates; Prospective Studies; Saudi Arabia; Struvite; Uric Acid; Urinary Calculi; Urolithiasis; Young Adult

Calcium substituted trimagnesium phosphate with the general formula Ca(x)Mg((3-x))(PO(4))(2) (0 < x < 1.5) was synthesized by calcination of powder mixtures with the appropriate stoichiometry and reacted with 3.5 M diammonium hydrogenphosphate solution to form a cementitious matrix of magnesium ammonium phosphate hexahydrate (struvite). The degree of ionic substitution was shown to influence physical cement properties; clinically suitable cement formulations with setting times in the range 5-15 min and compressive strengths of >50 MPa were obtained for x ≤ 0.75 together with a grinding time ≥ 1 h and a powder to liquid ratio ≥ 2.5 g/ml. The cement cytocompatibility was investigated by culturing human osteoblast cell line MG63 on cement surfaces demonstrating pronounced cell growth during 13 days cultivation.

Topics: Bone Cements; Bone Substitutes; Calcium Phosphates; Cell Line; Cell Proliferation; Compressive Strength; Humans; Magnesium Compounds; Mass Spectrometry; Materials Testing; Microscopy, Electron, Scanning; Models, Chemical; Phosphates; Porosity; Powders; Struvite; Time Factors; X-Ray Diffraction